Update NSPR to 4.12 and NSS to 3.23 on iOS

nss/lib/freebl/mpi/mpmontg.c

Index: nss/lib/freebl/mpi/mpmontg.c
diff --git a/nss/lib/freebl/mpi/mpmontg.c b/nss/lib/freebl/mpi/mpmontg.c
index 9667755d0349a26184516c23cf32fd0afb5492b2..c14b104d998415cf8d3a0347f8d5c5776b827da3 100644
--- a/nss/lib/freebl/mpi/mpmontg.c
+++ b/nss/lib/freebl/mpi/mpmontg.c
@@ -371,12 +371,12 @@ mp_err mp_exptmod_i(const mp_int *   montBase,
 
   MP_CHECKOK( mp_init_copy(&oddPowers[0], montBase) );
 
-  mp_init_size(&power2, nLen + 2 * MP_USED(montBase) + 2);
+  MP_CHECKOK( mp_init_size(&power2, nLen + 2 * MP_USED(montBase) + 2) );
   MP_CHECKOK( mp_sqr(montBase, &power2) );	/* power2 = montBase ** 2 */
   MP_CHECKOK( s_mp_redc(&power2, mmm) );
 
   for (i = 1; i < odd_ints; ++i) {
-    mp_init_size(oddPowers + i, nLen + 2 * MP_USED(&power2) + 2);
+    MP_CHECKOK( mp_init_size(oddPowers + i, nLen + 2 * MP_USED(&power2) + 2) );
     MP_CHECKOK( mp_mul(oddPowers + (i - 1), &power2, oddPowers + i) );
     MP_CHECKOK( s_mp_redc(oddPowers + i, mmm) );
   }